Applied Research

SSP&A's recognized expertise in groundwater, geochemistry, and environmental science has led to several ongoing research projects.

Fate and Transport of PCBs in the Subsurface

SSP&A served on an expert panel assembled by the Texas Eastern Transmission Corporation. The charge to this panel was to develop feasible remedial alternatives for sites where soil and groundwater were contaminated with polychlorinated biphenyl (PCB) compounds. Dr. Charles Andrews, President of SSP&A, served as Director of this panel that defined the chemical properties of the PCBs and their degradation products. The panel conducted laboratory and field studies of biodegradation, surfactant chemistry and transport, PCB transport and sorption, and the behavior of DNAPL in the subsurface; and field testing methods for PCB solubilization and recovery in fractured and porous media.

Research Efforts at the University of Alabama

Dr. Chunmiao Zheng, developer of the MT3D code and liaison of SSP&A, leads an interdisciplinary research team at the University of Alabama to develop a framework for designing pump-and-treat groundwater remediation systems. The project integrates groundwater simulation, optimization, and parameter estimation techniques to design groundwater pump-and-treat systems that meet physical, environmental, and budgetary constraints. Key components of the framework are Modflow and MT3D, the most popular flow and transport simulation models used in groundwater remediation designs. These simulation models are being coupled with an optimization model to automatically determine optimal well locations and pumping/injection rates under realistic field conditions.

Parameterization and Predictive Analysis in Environmental Modeling

SSP&A is collaborating with Dr. John Doherty of Watermark Numerical Computing (creator of PEST) to undertake collaborative research to improve environmental data processing through the use of numerical models, pooling resources and expertise to improve the use of computer simulation in environmental management. The theme of much of this research is parameter estimation and predictive uncertainty analysis.

Assessment of Performance Limitations of Soil-Vapor Extraction

SSP&A participated in a comprehensive assessment of soil-vapor extraction (SVE) as a remedial technology for volatile organic compounds. The study was initiated as part of an evaluation of the effectiveness of a SVE system in operation at the site. Although the extraction system had removed a significant quantity of volatile organic compounds from the soil, clean-up levels had not been met and the mass of contaminant remaining was found to be several thousand times greater than that predicted by the initial studies on the performance of the extraction system. Site conditions such as variability in the physical and chemical characteristics of the soils were found to have a profound influence on the performance of the soil-vapor extraction system. The work summarized the fundamental chemical and physical phenomena that can influence the effectiveness of SVE systems on a practical field-scale, and described the scientific basis upon which the performance of the systems can be evaluated and predicted.